The generation and characterization of mouse strains harboring genetically predetermined pathobiological syndromes is critical to biomedical research, and researchers at The Jackson Laboratory (TJL) are at the forefront of this endeavor. Scanning electron microscopy (SEM) represents a powerful method for imaging, documenting and quantifying in situ the morphological changes in cells and tissues associated with normal and induced genetic variation. Over 80% of TJL research staff rely upon SEM for such characterization. The Biological Imaging Service currently operates a twenty-year old scanning electron microscope. Due to age, its technology is outdated, its application is inflexible, resolution is limited and instrument performance is increasingly unreliable. Higher levels of resolution, variable pressure operation, multiple specimen holder, viewing chamber, flexible stage movement and digital image capture are considered state-of-the-art features; all are available on the Hitachi S-3000N Variable Pressure Scanning Electron Microscope. This unit is fitted with a cooling stage for optimal preparation of water-containing specimens and its ability to operate variable pressure mode permits image collection of uncoated specimens introducing time and cost savings. Physical constraints and finite stage movement of the current SEM limit the number of samples that can be loaded and analyzed; digital data collection is not possible. The Hitachi-S3000N offers users multi-specimen capabilities and networked digital image acquisition, elemental analysis and post processing management. The Hitachi S-3000N Variable Pressure Scanning Electron Microscope would fulfill the urgent and unmet SEM needs of TJL's staff. Introducing a stable instrument that enhances the scope, quality and speed of data collection will further advance 28 NIH-funded research programs of 15 investigators on campus and support the development of new NIH applications.